Add indices to state group tables

synapse/storage/schema/state.sql

@@ -31,3 +31,16 @@ CREATE TABLE IF NOT EXISTS event_to_state_groups(
     event_id TEXT NOT NULL,
     state_group INTEGER NOT NULL
 );
+
+CREATE INDEX IF NOT EXISTS state_groups_id ON state_groups(id);
+
+CREATE INDEX IF NOT EXISTS state_groups_state_id ON state_groups_state(
+    state_group
+);
+CREATE INDEX IF NOT EXISTS state_groups_state_tuple ON state_groups_state(
+    room_id, type, state_key
+);
+
+CREATE INDEX IF NOT EXISTS event_to_state_groups_id ON event_to_state_groups(
+    event_id
+);